Bhopal: Six farmers were killed and several others injured in western Madhya Pradesh’s Mandsaur on Tuesday when the police opened fire during protests for debt relief and better farm prices.

Soon after the incident, hundreds of irate farmers torched two police stations, eight trucks, an ambulance and two motorbikes at different places in the region ravaged by drought and farm suicides.

The administration rushed extra forces and imposed curfew restrictions in the district headquarters town of Mandsaur, some 350 km from state capital Bhopal.

Internet services were also suspended in areas such as Mandsaur, Ratlam and Ujjain to prevent protestors from “fuelling further unrest” through inflammatory posts on social media.

Spiralling farm protests in BJP-ruled Madhya Pradesh and neighbouring Maharashtra pose a challenge for Prime Minister Narendra Modi, who has promised to double farmers' incomes over the next five years. Farmers last week started protests in both the states, dumping vegetables and milk on roads.

Ujjain divisional commissioner O M Jha said the police had to open fire to control stone-throwing mobs. Two persons died on the spot and four others succumbed to injuries during treatment.

"Police started firing to disperse the crowd. Farmers were not carrying weapons," said Gajendra Tokas of the Rashtriya Kisan Mazdoor Sangh, which launched a 10-day agitation on June 1.

State home minister Bhupendra Singh denied that the police opened fire, saying that "anti-social" elements in the crowd fired bullets.

On Monday night, demonstrators broke the gates of railway crossing in Mandsaur town and unsuccessfully tried to uproot railway tracks, the police said.

One police sub-inspector lost one of his eyes in stone pelting. Madhya Pradesh chief minister Shivraj Singh Chouhan convened an emergency meeting of his Cabinet to take stock of the situation. He ordered a judicial probe into the police firing.

He also announced an ex-gratia of Rs 10 lakh to the families of those killed and Rs 1 lakh for those injured.

"The state government is sensitive to farmers’ demands and stands by them. But, Congress, through conspiracy, tried to fuel violence," the chief minister said.

The violence also sparked a political slugfest. “This govt is at war with the farmers of our country,” Congress vice-president Rahul Gandhi tweeted.